Project Summary The use of electronic cigarettes (e-cigs) has increased at an alarming rate among youth and young adults, despite critical knowledge gaps on their toxicity and potential health effects. E-cig devices work by heating a mixture of chemicals (e-liquid) with a metallic coil to generate a fine aerosol, which is inhaled by the user. Several metals, including lead and nickel, have been found in e-cig aerosols and are known lung toxicants; however, there is little information on how patterns of e-cig use impact exposure to metals and how these metal exposures may be associated with pulmonary health effects. In addition, despite the FDA's partial ban on flavored e- cigarettes, a new type of disposable e-cig (e.g. Puff Bar) has been recently introduced in the market targeting youth and young adults with sweet and fruity flavors; thus, we would like to evaluate how the use of these new devices affects exposure to metals and lung function. The recent e-cigarette, or vaping, product use-associated lung injury (EVALI) outbreak underscores the need to study how e-cig use may be associated with respiratory outcomes. Spirometry, a reproducible test of pulmonary lung function (PFT), allows assessment of early airway obstructive or restrictive processes. We hypothesize 1) new disposable e-cigs on the market (i.e. puff bars) are also a source of metal exposure, 2) e-cig user's vaping regimen affects the degree of metal exposure, and 3) that toxic metal exposure can have negative effects on respiratory health outcomes measured through reproducible pulmonary function tests, such as spirometry. Thus, our specific aims are 1) to measure metal exposure from new and emerging e-cig devices, 2) evaluate the association of e-cig use with pulmonary health measures, and 3) to assess the potential for metals from e-cigs to explain, at least in part, the measured pulmonary health effects. To achieve our goal, we will add pulmonary outcome measures to the remaining 25 POD e-cig users and 25 control participants from our R01. We will recruit an additional 25 e-cigs users of new disposable e-cigs (including Puff Bars) and 25 matched non-users to characterize pulmonary outcomes (Reductions in the forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and diffusing capacity of carbon monoxide (DLCO)), measures of metals in aerosol from their devices, and measures of internal exposure to metals in urine and blood at 0 and 6 months. We will verify e-cig use by urine cotinine and potential tetrahydrocannabinol (THC) use by urine toxicology test. Policy and research impact: In light of the recent EVALI outbreak, and the proliferation of new flavored disposable e-cig devices, there is an urgent need to understand exposures resulting from these devices. This study will generate critical data to inform FDA for e- cig regulation targeted at curbing the increasing prevalence use among youth and young adults, as well as to plan future interventions to limit adverse exposures and health outcomes.